Theorem subgex 13979

Description: The class of subgroups of a group is a set. (Contributed by Jim Kingdon, 8-Mar-2025.)

Assertion

Ref	Expression
subgex	|- ( G e. Grp -> (SubGrp ` G ) e. _V )

Proof of Theorem subgex

Dummy variables s w are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		df-subg 13973	. . 3 |- SubGrp = ( w e. Grp |-> { s e. ~P ( Base ` w ) | ( w ↾s s ) e. Grp } )
2		fveq2 5695	. . . . 5 |- ( w = G -> ( Base ` w ) = ( Base ` G ) )
3	2	pweqd 3693	. . . 4 |- ( w = G -> ~P ( Base ` w ) = ~P ( Base ` G ) )
4		oveq1 6092	. . . . 5 |- ( w = G -> ( w ↾s s ) = ( G ↾s s ) )
5	4	eleq1d 2307	. . . 4 |- ( w = G -> ( ( w ↾s s ) e. Grp <-> ( G ↾s s ) e. Grp ) )
6	3, 5	rabeqbidv 2816	. . 3 |- ( w = G -> { s e. ~P ( Base ` w ) | ( w ↾s s ) e. Grp } = { s e. ~P ( Base ` G ) | ( G ↾s s ) e. Grp } )
7		id 19	. . 3 |- ( G e. Grp -> G e. Grp )
8		basfn 13411	. . . . . 6 |- Base Fn _V
9		elex 2833	. . . . . 6 |- ( G e. Grp -> G e. _V )
10		funfvex 5712	. . . . . . 7 |- ( ( Fun Base /\ G e. dom Base ) -> ( Base ` G ) e. _V )
11	10	funfni 5483	. . . . . 6 |- ( ( Base Fn _V /\ G e. _V ) -> ( Base ` G ) e. _V )
12	8, 9, 11	sylancr 418	. . . . 5 |- ( G e. Grp -> ( Base ` G ) e. _V )
13	12	pwexd 4318	. . . 4 |- ( G e. Grp -> ~P ( Base ` G ) e. _V )
14		rabexg 4279	. . . 4 |- ( ~P ( Base ` G ) e. _V -> { s e. ~P ( Base ` G ) | ( G ↾s s ) e. Grp } e. _V )
15	13, 14	syl 14	. . 3 |- ( G e. Grp -> { s e. ~P ( Base ` G ) | ( G ↾s s ) e. Grp } e. _V )
16	1, 6, 7, 15	fvmptd3 5799	. 2 |- ( G e. Grp -> (SubGrp ` G ) = { s e. ~P ( Base ` G ) | ( G ↾s s ) e. Grp } )
17	16, 15	eqeltrd 2315	1 |- ( G e. Grp -> (SubGrp ` G ) e. _V )

This proof depends on syntax axioms:   -> wi 4   = wceq 1402   e. wcel 2209   {crab 2532   _Vcvv 2821   ~Pcpw 3688   Fn wfn 5372   ` cfv 5377  (class class class)co 6085   Basecbs 13352   ↾_s cress 13353   Grpcgrp 13805  SubGrpcsubg 13970

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-14 2212  ax-ext 2220  ax-sep 4249  ax-pow 4311  ax-pr 4346  ax-un 4578  ax-cnex 8270  ax-resscn 8271  ax-1re 8273  ax-addrcl 8276

This proof depends on definitions:  df-bi 117  df-3an 1011  df-tru 1405  df-nf 1514  df-sb 1816  df-eu 2089  df-mo 2090  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-ral 2533  df-rex 2534  df-rab 2537  df-v 2823  df-sbc 3052  df-csb 3148  df-un 3224  df-in 3226  df-ss 3233  df-pw 3690  df-sn 3715  df-pr 3716  df-op 3718  df-uni 3936  df-int 3971  df-br 4131  df-opab 4193  df-mpt 4194  df-id 4438  df-xp 4780  df-rel 4781  df-cnv 4782  df-co 4783  df-dm 4784  df-rn 4785  df-res 4786  df-iota 5337  df-fun 5379  df-fn 5380  df-fv 5385  df-ov 6088  df-inn 9305  df-ndx 13355  df-slot 13356  df-base 13358  df-subg 13973

This theorem is used by:  isnsg  14005